An operation control device is provided with: a manually-operating unit having a joystick knob capable of intermittently operating in two directions; a knob displacement detector for generating knob displacement information of the knob; a controller for converting an amount of knob displacement obtained from the knob displacement information into an amount of force; and a force imparting unit for imparting a force corresponding to the amount of force to the knob when the knob is operated, wherein when the knob passes through one or more intermittent positions from a starting position to be operated to a terminating position, the controller sets in such a manner that an amount of force at one or more intermittent positions is increased in stages from the starting position side toward the terminating position side.